Working machine with crawler

Abstract

A working machine with a crawler includes a lower traveling body having a pair of crawlers, an upper turning body, an extension beam installed rotatably to be parallel in a longitudinal direction of the crawler, a fitting portion opened in a side frame of the crawler, a fixing pin fixing the extension beam to the side frame, a fixing pin insertion hole, a fixing pin fitting hole, and a reinforcement rib, in which the extension beam extends to be inserted into the fitting portion, and the reinforcement rib is provided at a center portion of an opening of the fitting portion, and the fixing pin fitting hole is disposed at a position which is deviated from an imaginary center line extending along a longitudinal direction of the fitting portion from the center portion and does not interfere with the reinforcement rib.

What is claimed is: 
     
       1. A working machine with a crawler, comprising:
 a lower traveling body which includes a pair of crawlers and a car body; 
 an upper turning body which is turnably supported by the car body; 
 an extension beam which is installed rotatably on a distal end side of an axle of the car body to be parallel in a longitudinal direction of the crawler; 
 a fitting portion which is open in a side frame of the crawler; 
 a fixing pin which fixes the extension beam inserted into the fitting portion to the side frame; 
 a fixing pin insertion hole which is perforated in the extension beam and into which the fixing pin is inserted; 
 a fixing pin fitting hole which is perforated in the fitting portion and into which the fixing pin is inserted; and 
 a reinforcement rib which extends in a direction perpendicular to a side surface of the side frame on a lower surface of a bottom plate of the fitting portion, 
 wherein the extension beam extends such that the extension beam is inserted into the fitting portion, the fixing pin is inserted into the fixing pin fitting hole via the fixing pin insertion hole, and thus, the extension beam is fixed to the fitting portion, 
 wherein the reinforcement rib is provided at a center portion of an opening of the fitting portion, and 
 wherein the fixing pin fitting hole is disposed at a position which is deviated from an imaginary center line extending along a longitudinal direction of the fitting portion from the center portion and does not interfere with the reinforcement rib. 
 
     
     
       2. The working machine with a crawler according to  claim 1 ,
 wherein two pairs of the axles are provided in the car body, 
 wherein a pair of the fitting portions is open in the side frame, 
 wherein the fixing pin insertion holes are respectively provided at positions which are deviated toward an outer side of the extension beam so as to be paired from the imaginary center line in a longitudinal direction of the extension beam passing through a center of the extension beam in a width direction, and 
 wherein the fixing pin fitting hole is provided at a position corresponding to the fixing pin insertion hole. 
 
     
     
       3. The working machine with a crawler according to  claim 2 , further comprising:
 an extendable member which moves the crawler close to or away from the car body; and 
 an extendable member coupling bracket which couples a distal end of the extendable member to the side surface of the side frame on a side to which the extension beam protrudes from the fitting portion, 
 wherein when a protrusion portion of the extension beam which is inserted into the fitting portion and protrudes from the side frame is folded, the fixing pin insertion hole is located outside the extendable member coupling bracket. 
 
     
     
       4. The working machine with a crawler according to  claim 3 , further comprising:
 a lock hole into which the fixing pin is inserted via the fixing pin insertion hole when the protrusion portion is folded and which fixes the extension beam on a side surface side of the side frame.